Dirac Freezing: A Universal Mechanism of Singular Second-Class Constraint Collapse
Year: 2026
Type: preprint
Abstract: A universal mechanism---\emph{Dirac freezing}---is identified through which a constrained dynamical system loses all physical degrees of freedom without producing gauge symmetry. The loss proceeds by a singular collapse of the constraint algebra into a maximally second‑class configuration. The frozen phase is separated from any dynamical phase by a finite rank gap and cannot be approached continuously; a universal barrier theorem is proved using rank semi‑continuity. Embedding the frozen sector into a dilaton shows that, while freezing is fine‑tuned under conservative evolution, dissipation or quantum tunneling drives it generically. Higher‑derivative terms evade it entirely. Extensions to field theory and gravity demonstrate that matter can freeze while leaving gravitational waves intact; a complete spacetime freeze requires breaking diffeomorphism invariance, which distinguishes it from Carroll and strong‑coupling limits. In an expanding universe, Hubble friction confines freezing to the dark‑energy‑dominated era, producing a characteristic kink in the growth of structure, a non‑phantom equation of state, and a non‑thermal small‑scale cutoff in the matter power spectrum. In the dissipative quantum regime, field‑mode adiabatic invariants decay exponentially, and any initial entanglement is destroyed irreversibly. This yields a quantitative, falsifiable signature that cleanly separates Dirac freezing from ordinary decoherence.
Author: Huang, Youming
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7169687080
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